It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that a delegation of Jews came to the service of the Prophet (peace and blessings be upon him) and said: O Abul Qasim (peace and blessings be upon him)! We want to ask you a few things, please answer them for us, because only a prophet can know them. Among the questions they asked was this: Before the Torah was revealed, which food did Jacob (peace be upon him) make unlawful for himself? The Prophet (peace and blessings be upon him) said: "I ask you by Allah, Who revealed the Torah to Moses (peace be upon him), do you not know that once Jacob (peace be upon him) became very seriously ill, and when his illness became prolonged, he made a vow in the name of Allah that if Allah granted him recovery from his illness, he would make his most beloved drink and his most beloved food unlawful for himself? And among foods, he loved camel meat the most, and among drinks, its milk was the most beloved to him?" They said: By Allah! It is so.